Method of reworking finely divided metal particles



Jun@ la 331.l

METHOD 'OF REWORKING FINELY' DIVIDEDMETAL PARTCLES J. SHMELLER, su@LSIQSBS Grginal Filed Apxfil 3, 1926 2 Sheets-5h69?. l

I N VEN TOR.

Jo/Hi 50/1 mel/ver, 5l:

A TToRNEYs Jim@ 69 931- J. SCHMELLER, SR

METHOD OF REWORKING FINELY DIVIDED METAL PRTICLES Original Filed April3, `11.926 2 Sheets-Sheet 2 w/ MW mm fr, N R d f MMQWW I@ A .r 5 b fa Mf L M/ Jgd@ rnengedfJnnefglef 51931 V UNITEp STAT-Es HJEISSUED PATENToFFlc-E JormscHMELI-.m or mxnwoon, omo, assumer. 'ro scimmia. nommecorrrm,- or cLEvELANn, omo, a conroaarrou or omo.

METHOD or nEwoaxINe rINmY mvmnn METAL PAnrIcLEs origina; application,med piu s, 1926ser1a1' No. salsa Divided anatun'appncaaon mea February8,

1928.-. serial No. suaves.

like materialfrom finely divided stock for` l casting purposes. Anotherobject of vthis in- This invention as indicated relates. a method ofremelting-finely dividedv particles of metal such as aluminum or brassor alloy borings, turningsand thel like, and making castingsoringotstherefromas a single, con,-

'as discarded castings, sheets and scrapof every.; character, as wellasborings,-turnings andjfskimmingsandwhich will produceas acontinuousoperation. supplyof molten aluminum. suitable. for' casting`cr ingct` purposes.

Heretofore the remelting of.: aluminum, particularly. nely dividedaluminum such as has been mentioned, has involvedmany diflicultiesbecause of the light character of the stock and the readiness withwhichthe same is oxidized.'` The processof recovering said metal from suchfinely divided stock in most instances heretofore has involved apreliminary melting at low heat-in small individual furnace pots stirredby hand or. by rotary stirring devices, and then casting into ingotsfollowing by remelting of said mgotsg preliminary to use in makingvarious articles of 'manufact-ure. Open furnaces :for -producing ingotsfrom finely divided stock, also have been used, but such apparatuscannot be used to bringthe metal to casting heat because ofthermallosses. It has not been the practise heretofore with a single apparatusto remelt finely divided aluminumV or the like, and to maintain the sameat any adequate temperature as a liquid supply of alumlnum from whichthe necessary quantities for casting purposes mi ht be drawn in'tocasting ladles as requir The rincipal lobject of the presentinvenvtion,'t erefore, is' to provide an limproved method of supplyingmolten aluminum or vention is toA provide a continuous process forfurnishings molten aluminum sup l whereby inely divided aluminum maybe-the stock v for remelting..`v and wherein the recovery from such stockmay be equal to or in excess of the values for such stock determinablein an industrial assay laboratoryl thoroug intermixtuie' of the addedstock with the molten mass and removal 'of all which will operatecontinuously and with a minimum expenditure of fuel and labor andmaximum out-putI of product. A still fur. y ther object of the inventionto provide a furnacefwherein agitating means will operate verticall iinthe molten metaljat the chargi 0f si ev of the furnace` and insuregrease and vthe foreign Amatter therefrom# v preliminary to the carryingof the pure mol;

ten metal into the discharge' side of said furnace, and through thisagitating action, termed vertical -puddlin to im rove the quality of themetal, pudl "ng out t e oxides n n and foreign substances including freeiron borings which are caused to float and may be. readilyr skimmedfrom! the top. The grease is removed in the first chamber and usedasfuel.

A still 'further object of the invention is to provide a furnace for thepurpose specified without a draft or exit for the gases other than thoseprovided by lateral o enings in the Walls of the upper portion of t efurnace yand, wherein the amount of oxygen or air charged into thefurnace is kept at a minimum, and below the point necessary for completecombustion of the fuel gases admitted thereto. Still another object ofthe invention is to provide a counter-balance for the mechanism of thefurnace whereby the agitating devices may be easily removed from Ithefurnace bath and also to provide an ad-A justinent for` suchagitatingdevices whereby the position of the same, relative' to the liquidcontent of the furnace, may be varied as desired. Other and furthervobjects of the such disclosed lmeans and mode illustrating,

however, but several of various ways inl wslich the principle of thevinvention may be u In said annexed drawings:

Fig. 1 is a Side elevation partiauy in secs tion of a furnaceinstallation embodying the principle ,of my invention; Fig. 2 is a topplan view of the a paratus shown inFig. 1';

ig. 3 is a sectiona plan view of the furnace proper; Fig. 4 is a sideelevation of the grid; Y

ig. 5 is atop plan view of the grid; and Fig. 6 is an enlarged sectionaldetail view showing the grid attaching means.

As has beenindicated, the general practice heretofore followed inreworking orremelting finely divided aluminum has been to place the samein open furnaces and to agitate the same by hand or by means ofmechanically rotated propelling devices. Such method of remeltinginvolves thermal losses and the average heat therein is below goodcasting temperature. This requires castin into ingots and thereafterremelting of suc in ots to obtain metal which is of high enougtemperaturefor use in casting into the various articles of' commerce forwhich the metal is employed. This procedure `entails a remelting loss offrom 1 to 2 per cent. as well as the cost of the additional remeltingoperation. Thus to obtain a quan- 'tityl of aluminum sufficient forfoundry purposes it is necessary to employ a large number of laborersand accumulate the product from a series of individual furnace pots or`open furnaces in a remelting furnace in order to carry on the castingoperations.

- My improved method of reworking finely I A divided aluminum consistsin preparing a bath of molten aluminum into which the finely divided,aluminum is fed as raw stock,

and in continuously agitating the' portion of said bath to which saidstock is added in order that it may be rapidly absorbed into the moltenmass in said bathand the impurities such as oil grease and dirt, freeiron, oxide and the like, maybe rapidly freed therefrom, and inWithdrawing'from another por-` tion of said bath the aluminum freed ofsuch impurities and at a temperature suitable for casting. My method ispreferably carried one of drawings, the furnace 1 comprises a brickstructure formed of piers and arches and promay be varied in accordancewith special re-v quirements or with the character of the stock and therate of use of the product or other conditions. At a point above thelevel ofthe molten metal in `sa1d chambers, charging and skimming doorsare provided.

While a singlefurnace unit might be pro vided, it has been found moreeconomical to construct` three or more furnace units in series in a sinle structure, as shown, which may besimultaneously operated by a crew ofWorkmen more economlcall than a single lfurnace unit or a series of inependent furnaces. Likewise the operating mechanism for a of furnaceunits may be more economically installed and the heat losses may beproportionately reduced.A In the drawings, therefore, I have illustratedthree furnace units in series. The units are each operatively distinctfrom the others and a different alloy may be run in each chamber. Eachof said units is divided centrally by a partition wall 5 so as toprovide on one side a combined charging and agitating chamber 2 throughwhich the metal stock is fed into the furnace and on the opposite sidewith a heating chamber 3 for the rece tion and temperature control ofthe castlng supply of molten metal.

The dividing wall 5 preferably extendsy from the ground to the roof ofthe furnace. Beneath each of the'series of chambers 2, 3, arched heatingchambers 6, 7, extend. The

iioors 8, 9, of the communicating chambers 2,

3, rest upon these arches and are packed with ganister or other heatresisting material, and the walls of said chambers are formed of orlined with lire-brick. Where da series of three furnace units isprovided, it is found more economical of f-uel to have the divisionwalls between the several casting sections extend only to a pointslightly above the side doors so that the gases in the upper part of the4furnace on the respective sides of the dividiv wall 5 may travelfreelyinto any nxe three adjacent charging chambers or the three adjacentcasting chambers. Centrallyy of the outer wall o f eachlof the charging.chambers Ya chargin adapted to be closed by a sli 'ng charging door 12formedof lire brick, is provlded.

lire-brick door 14. Within the upper openk portion of the series ofcasting chambers, a.

opening 11l y fuel supply nozzle .(notshown) is provided throu h which`atomized crudeA oil or some such el mixture may be projected into thecasting u chambers. Counterweights (not shown) may be individuallyapplied to each of the doors of the several charging andcasting chambersso that the same may be readily lifted and lowered when the furnace isin operation. In addition to the fuel supply charged directly into theupper portion of the casting chambers above the metal reservoirs,rovision is made for the heating of each of said series of furnaces bymeans of nozzles (not shown) within one end of the arched chambers v6and 7 heretofore described. An opening- 10 is provided at the end of thechamber 7 to permit egress of excess hot gases at that end of thefurnace, and this lower opening also constitutes a safety overflow intheevent of a leak in the metal reservoirs.

On the dischargeor'casting side of the.l

furnace, a tap hole 1'5 and spout 16.is provided adjacent lthe centrallower portion of each ofthe metal reservoirs. Along each lateral side ofthe furnace tanks or troughs 1,7, 18, adapted to be filled with waterare ,provided 4into which hot skimmings from the top surface of the`'molten metal may be dropped as'the occasion arises. l The depositingof the skimming in the troughs sepau v -provided t rough which the lowerend ofthe rates the aluminum from the ,dirt and the aluminum may beagain used as -part of a charge for the furnace.l u

At each end of the charging side of the series of furnace units adjacentthe top arch an opening 2 1 is provided, over which a door 22 lined withlire-brick is hung, and through which the furnace gases lcarrying lightdustA and dirt and the burningparticles of grease and oil, which ma fbemingled therewith,

partiallyescapehese doors Lalsoserve as safety orexplosion doors andpreventun due pressure within the furnace. 4

It will be noted that-above the surface of the molten massjof metal 'thefurnace carries va heavy bank of hot gases whichare -sufcient 'inquantity to completely fill the space 'referred to and that such gasesare at a slightly higher pressure than the outside atmosl an loftheseveralzo. ,enin s intothe 'char'l'n y P g g1 g Lthemo ten massofmet'al.

chambers,1but little air enters at such points because vfof vthe;higherpressure vofithe Qgases withinithe 'furnac'e which seelrfegressy:ii-...such

time."*EachA f thefend: andinternal.wallsal bothfthe `f-:hargi-ng.-fandwast'ingrehaibers;

charge might freeze and require a high degree of heat to remelt. f

The means' for agitating the molten mass of metal on the charging sideof the furnace emergency use, at times 'whennthe furnace will now bedescribed and while al particular embodiment of such apparatus'isillustrated, it is to be understood that other mechanism foraccomplishing the same `result may be employed instead of thatillustrated. Within each of the charging chambers a grid or stirringmember 31 is provided which is of an outline similar to that of thefurnace chamber and of slightly smaller size than said chamber.Said-member comprises a heavy central portion or boss, 32, and-.aseriesof radial arms 33gradually"decreasingin thickness toward theirfree endsra'nd'joined at such ends by a rim 34 of metal corresponding inoutline to the outline ofthe furnace chamber and spaced from the wallsthereof. Between the radiating arms spaces 35 are provided through whichthe molten metalv may freely pass as the grid is plunged downwardly intothe molten metal and withdrawn 'therefrom by themechanism presently toAbe described. l

Centrall ofthe grid a beveled socket 36 1s operating stem 37 of theagitating device may be received. The lower end of the stirring rod oroperating member is providedgwith notches `38 ,to receive projections 39uponv a Y series of shoes 41 which have beveled sides 42 terminating inoutwardly extending flanges, 43. In order to engage thegrids .with theoperating rods, thelower'ends of said rods are inserted throughthecentral apertures of said, grids land the shoes .or tapered `platesvare engaged with said rods and the. id lowered on the outer beveledVsurfaces o said p1ate`s xl :about eachrod above thegrid prevents theplunged into f burnin out of the rod as 1t -is through said furnaceroof. These rollers are preferably anged rollers engaging in pairs onopposite sides of the square operating rod and suitable lubricatingdevices for said rollers may be provided. The rod is set angularly toprovide for easyl removal of oxide and refuse or skimming.

, The upper end of the rod is provided with an aperture 51 for attachinga lifting cable 52. Adjacent the upper end of the rod .an

lextension arm 53 is provided to which agrid depressing cable 54 issecured. The respective cab-les are passed about pulleys 55, 56, securedto fixed supports above the rod and adjacent the roof of the furnacerespectively and thence passed in opposite directions to a pair ofsheave wheels' 57, 58 mounted upon a shaft 59 preferably located on aplatform 6l above the levelof the furnace roof. The shaft carryingr therespective-pairs of sheave wheels is oscillated by suitable mechanismshown in this instance. as an electric motor com' )lete rotation.` ofthe 62 coupled with a suitable reducin r gear 63 to a crank arm 64 which11s joined y -a connecting rod 6 5 with a similar crank arm 66 on theoscillating shaft. The proportions of weights for the grids andsupporting arms and spring take-up means to prevent excessive. strainsnponthe mechanism. Accordingly, a spring 71 is'inserted' in the line ofthe grid depressing cable and conntm'weight 2 is carried at the end of4the grid elevating cable. 'lhecounterweight is adapted tobi-ar againsta stirrup bar 73 supported on a pair of springs 74 which are secured toa fixed support 76 above the top range of motion of the counte'rweightso'as to hold said bar in the path of movement of the counterweight whenthe grid is drawn from the metal bath. 'The counter-weights are guidedupon a pair of bars 77 supported at each end in' the frame of theoperating mechanism and springs 78 on said bars serve. as buli'ers. Anadjusting pulley 81 is provided in the line of grid elevating. cablepreferably supported on a pair of arms 82 pivotcd to the frame ata pointadjacent the sheaves and supporting said .pulley rearwardly inalignment. therewith. Each of said pairs of frames is provided with astationary nut 83 through which the upper end of a screw threaded rod 84is adaptedto engage. `A hand-wheel 85 is attached at the lower end ofsaid rod whereby said pulley may be adjustedupwardly or downwardly tothe necessary ,extent to lift the grid to any point desired with respectto the liquid mass in the furnace chamber. Thus by turning the screw inone direc-tion the' grid may be full)1 withdrawn from the ybath ofliquid metal and heldl at a point above the charging opening ofitsfurnace. When adjusted in the opposite'direction, the Grid may beforced'to a considerable depth within the molten mass of lmetal as itreaches its lowest limit of motion in thel chargingside of the furnace.'lhespring provided in the grid'dep-ressing cable is put under tensionas the grid is elevated and is relieved of the larger part of suchtension when the grid is lowered to its usual operative position. safetydevice when the grid strikes an obstruction in its descent. Thuscomplete control of the agitating mechanism of the furnace is providedboth asto the starting and stopping of the agitation and the position otthe agitator with res ect to the molten mass of metal maybe rea ilyadjusted.- Through a suitable rheost'at the motor speed of the operatingdevice may be controlled and thus the rate of agitation may beregulated.

VThe construction ofthe apparatus has been described. The method ofoperationwillnow be briefly outlined.

In order to start an individual furnace or a series of furnaces, theburner above the casting'or'dischargesidev of the furnaces is ignitedand the entire furnace structure is thor- Italso serves as 'a' resllientoughly heated. The burner below the casting side also ma be used tocarryon the-heating more rapid y., It is ordinarily not necessar to use theburner beneath the ioor of the c urging chamber as the heat -in thecasting chamber is adequate to bringthe temperature of the entirestructure to the proper point; The charging side of the furnace is thenfilled with ingot-s and scrap sulicient in quantity to form a liquidmass of metal of substantial depth in the two furnace chambers when thesane has been melted. When the charge in ldie casting side of thefurnace becomes a molten mass and flows into the charging side of thefurnace through the aperture centrally of the dividing wall-of saidfurnace, the apparatus is ready to receiietinely divided stock on thecharging side. l-Vhen a suitable temperature has been attained, thelower burner may be extinguished if desired. 'lhe agitating mechanism ofthe furnace is then started and finely divided stock is supplied throughthe charging openings. -The grease and oil found upon the stock willprovide adequate fuelfor the (dial-ging section of the furnacetopmaii'itan a high temperature therein and the fuel in g. r am thecasting chambefwi-ilmantain theimolten mass at that side o f thefurnacefat the desired `rature foncasting. f

l e agitatlng mechanism 'f' continuous operation andthe chargin ldoorsvare `opened in 'succession .l and fine y vided aluminum for other' stockl(which it is desired to charge into the furnace is fed therein. Whenmoisture ispresent -in the raw stock, it

is' .desirable torst place thegreater portion of the char uponthe sillofthe char ing opening an after the chargingdoor has een closed to againopen said. door and push 'the dried mass fromA the sill into thefurnace.

The agitating 'devices ordinarily rise and fall `once ever two secondsalthough the speed may be c anged in accordance with the amount of metalinthe furnace,;the characterv of the raw stock,A and the rate-ofywithdrawal 2o on the casting side ofthefurnace;

As thev finely divided aluminum 1s fed into A s the furnace it isplunged beneath the surface of -the molten metalvthrough the action of-the grid and the particles are intermingled and combined with themolten massthrough the successive strokes of the grid. The'iinelydivided particles arethus-rapidly ,and completely -incorporated with themolten'mavss onv the chargin side of the furnace. 'Thei purer metal willescend .into the reservoir in the charging side-of the'furn'aceand asmetal is withdrawn from the ycasting side will low through the aperture'centrally of the base of the partition wall of the. furnace and willrise. in the castin side of the furnace ltomaintain the level in te resctive sides of the furnace reservoir at a uni ormpint.y

Inthe casting side of the ffu-rnac'e the metal is exposed-to the directheatin 1actionv ofthe flame projected from` the nozz e adjacent theyl.upper portion of said section and may -also be subjected' to heat fromthe burner atthe base of the furnace-shouldsuch heating aetion berequired. The temperature o the furnace may thus `beregulated tomaintain the metal'in the furnaceat a suitable tempera-l tureforcasting.1 v

During the course of .thel operation the workmen about the furnace mayskim the sur-A face of the molten metalto .remove impurities fromtime totime. f Such skimmings may be dro d into the .tanksattherespective sideso iee furnaceandlater may be again ine `trodueed into the furnacethrough :the chargving.openings#along with other stock. usedft`o vfeedthe furnace. j f j It mayalso be 4found desirable to place into thefurnaceon the charging side', quantities.

efflux, such as cryolite, calcium chloride, zinc` chloride, and thelike,inonder to facilitate theremoval of impurities.

i Thus it will be apparent` the inethodandmechanismabove-described-.provide fora continuousfsupply of aluminum'for casting pur- 55.:poses'and-permittheuselfg-very finely di`tideanuminumwan which a v largeparcela age' of l.greaseand oil maybeintermin led -.andpermit` the reworking of such meta at 1a highrateofzspeedand with a recovery equal or'superiorfto-the quantities whichare ascertained to be' recoverable ,by"labo ratory' assays.

While reference has been made in the speciication and some of the claimsto the use of two chambers, it is to be understood that eguivalentconstruction such as a plurality o charging chambers and an associatedcasting chamber or a single charging chamber and a plurality of castingchambers associated therewith, would be within'the purview oftheinvention. Likewise Awhile the invention has been described asparticularly 1 adapted for use with nely divided aluminum,

itis to be understood that the process and `apparatus is not intended tobe limited to use Withthat metal or its alloys and may be-used with anyother inelydivided metal requiring similar treatment for successfulcommercial reworking.

Other modes .ofapplying theprinciple of my invention may be employedinstead of the one explained, change being made vas regards `the meansand the steps herein disclosed,

provided those stated byany ofthe'following claims or their equivalentbe employed.

I therefore particularly point out and dis- `tinctly-claim as myinvention:

l. In a method of melting and refining metal, the steps *which consistin applying heatto bring-fA the metal to a molten condition andthereafter maintainingv the" molten con ition fofv said metalv andreningv and deoxfidizingthe same by paddling the molten material from alosition above the level thereofdownwar yy in a substantially verticaldirection and'setting up aplurality of substantially vertical currentstreams of molten metaltointeract-upon each-other'.

In av methodlofmelting and refining aluminum, the stepsswhich consist inap ly'- ing heat to bringthe aluminum to .amo tencondition, and`vthereafter maintaining the molten condition of said aluminum and re-.iining and'deoxidizin'g the-same by.p1fddling the kmolten :materialfrom aiposition ve the vvlevel'thereof downwardly in a substantiallyvertical .direction and setting .upfaplu- 'rality of su bstantiaily'Vvertical4 .current 'streams of molten aluminum to'interact 'upon each.other.'

` L Y. I, 3. "Ina methodof meltingy and ',refipihg aluminum, .thestepswhich ,cnnsistinap lying heat to bring saidaluminum :to ai mo tencondition, maintaining a' reducing atmos- :p here over said molten mass,continuously puddling said molten! mass` from a .position above thelevelthereofdownwardly .ina substantially: vertical direction,addingsubdivided aluminiferous material to `said 'mass whilefcontinuingthe verticalpuddlingfof vertical direction continuousl deoxidize saidmolten mass `o aluminum.

5. A method of melting and refining aluf minum as asingle continuousoperatlon to produce a product suitable foruse in commercial fabricationwhich includes the steps of maintaining melting temperature in a..

mass of molten aluminumthrou h a source of heat applied indirectly tosaid mass of aluminum and puddlin said mass of aluminum' from a-positiona ove the level thereof downwardly in a substantiallyverticaldirection eontinuousl to refine and deoxidize said molten mass oaluminum.

6. A method of melting and refining alu-Y minum as a single continuousoperation to p roduce a product suitable for use in commercialfabrication which includes the steps of maintaining melting tem eraturein a massof molten aluminum, pu dling said mass of aluminum in asubstantially vertical direction from a point above said molten mass,addingmaterial to saidmass of molten aluminum from a point above thesame, and continuing to puddle the same in a substantially 'verticaldirection to carry such added material downwardly into said mass ofmolten aluminum, and settin up overlapping currents of molten meta toincorporate said.

added material and thereafter continuously puddling ina substantiallyvertical direction said mass of molten aluminum and added material toreiineand substantially to deoxidize all of said material.

.7. A method of melting and refining' aluminum as a single continuousoperation to produce a .product suitable for use in commercialfabrication whichncludes the steps of maintaining melting temperaturelina mass of molten aluminum, puddlng said mass of aluminum in asubstantiallyvertical direction from a point above said molten mass,adding raw aluminiferous material and suitable fluxes and continuouslypud-A dling the. same in a substantially vertical direction to carrysuch added material and ilux downwardly into said mass of moltenaluminum and setting up overlapping currents of molten metal toincorporate said added material and fluxes and thereafter continuouslypuddling in a substantially vertical direction said mass of moltenaluminum to refine and.-

' withdrawin and added material to refine and substantially to`deoxidize all of-said material.

Y 8. A method of melting and refining aliiminum as a single continuousoperation to vproduce a product suitable for use for commercialfabrication which includes the steps of maintaining meltin temperaturein coinmunicating masses o p aluminum, adding aluminiferous material toone of said masses, and withdrawing molten aluminum from the other ofsaid masses, applying heat adequate for casting purposes to one of saidmasses and puddling in a substantially vertical direction the other ofsaid masses, to incorporate the added material and refine the contentsof said mass, and to interchange heated metal between` said masses tomaintainadequate melting temperature in said puddled mass.

9.. A methodof melting and refining aluminum which includes the steps ofmaintaining melting temperature in communicating masses of'moltenaluminum in adjacent chambersz adding aluminiferous material containingrease and oil and other heat lproducing e ements to one of said massesin a reducing atmosphere' and heating said mass through the fuelmaterial thus added, and

molten aluminum from the other' of said masses after applying heatthereto adequate for casting purposes, and puddling the material in therst mass in a substantially vertical direction Ito incorporate the addedmaterial in a molten metal and refine said mass, and to'interchangeheated metal between said masses to maintain adequate meltingtemperature in said puddledmass.

10. A method of melting and refilling aluminum which includes the stepsof maintaining melting tem rature in two communicating-mass'es o moltenaluminum by heating one of-sid masses maintaining a blanket of reducinggases above said mass, feeding material into the other of said massesand thereafter puddling said material from the up r surface of saidmolten mass to. which .e material was added toward the bottom ofsaid'mass.

11. A method of meltin and refining aluminum which includes t e stepswhich consist in maintainingv themolten condition of said metal, addingaluminiferous material, carrying a percentage of impurities includingiron particles, to said molten material, and continuously paddling thematerial from a position above the, level thereof downwardly in asubstantially vertical drectionand setting up a plurality ofsubstantially vertical current streams of molten metal to interact uponeachother and to float any iron particles at the surface of s'aid metalbath, and skimming said iron particles and other impurities from thesurface of said bath.

12. A method of melting and refining metal. at 'high temperatures, whichMin'- cludes the steps which consistin -maintainf ing the moltencondition of saidmetal beneath a bank of hot gases having a reducingaction, and refining and deoxidizing the same by continuously puddlingthe molten lmaterial .from a position above the level thereof downwardlyin a substantially vertical direction and setting up a plurality ofsubstantially vertical current streams of molten metal to .interact uponeach other.

13. In a method of melting and refining metal at'high temperatures, thesteps which Aconsist in maintaining the molten condition of such metaland continously puddling the material from a position above, the levelthereof downwardly in a substantiallyvertical direction and setting up'a plurality of substantially vertical current streams *of molten metalto interact upon' each other and to oat any foreign particles withinsaid metal bath at the surface thereof. I

14. A-method of producing metal aluminum from secondary raw materialirrespec.

ltive of admixtures of' iron, oxides, alloys,

-iron particles and other impurities, skimand the like, which. includesthe steps of heating aluminum to form a molten mass, addin secondarymaterial from above the level o said lmolten mass, puddliiig the moltenmass of material from a position abovethe level thereof downwardly in asubstantially verticaldirection ,from a point above'the liquid' leveland setting up overlapping currents of molten metal to incorporate theindividual portions of added material to substantially of said masses, aplying heat to one of said masses and with rawingl molten metal from themass subjected to' heat for fabricating purposes.

18. In amethod of reworking finely divided aluminumf the steps whichconsist of maintaining separate vmasses of molten aluminum incommunication With one another through a narrow passageway adjacent thebase of said masses; heating one of said massesu and agitating theAother of said masses, addinmfinely ,divided aluminum to the massundergoingagitation and withdrawingmolten metal from the other mass of;

metal for fabricating purposes.

- 19. A `method pf melting 'and refining readily oxidizablemetal,consisting in' maintaining communicating masses of molten Ametal inagitation while -in a non-oxidizing deoxidize the molten mass, and tofioat said 'mingsaid impurities from the surface and drawing castingmetal from said mass.

15. yIn a method of melting and refining metal, the steps which consistsin applying heat to bring the metalto a molten condition, and thereaftermaintaining the molten condition ofsaid metal and refining and`deoxidizing the same by puddling the molten material 4from a positionoutside of the contents downwardly toward the bottom of said mass, andsetting up a plurality of interactcurrent streams of. mplten metalwithin saigdm'ass. l

16. A method of melting and refining aluminum consisting in heating oneof two commun-icating masses 'of'y molten metal whileagl tating themetal to cause interchan eof metal oetween said masses adding finelydivided aluminum to one of said masses and withdraw# ing molten metalfrom the other mass fof metal for fabricating purposes.

. 17, AJ method of. melting and` refining i aluminum as a single,continuous'operation l consisting in heating one of two communicatingmasses of molten aluminum while agitatf ing. the metal to causeinterchange of metal between said masses, 'adding material to one-heating directly the other4 of said masses,

fidizable metal to one of said masses, and withdrawing molten metal fromthe other ebruary, Y

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